The present subject matter relates generally to semiconductor devices, and more particularly to methods of patterning a platinum layer on a substrate.
Conventionally, aluminum and copper are widely used for metallization purposes in integrated circuits (ICs). However, humidity may cause reliability problems for ICs that utilize such metals. For example, in the case of electrochemical sensors, the ICs are commonly exposed to fluids. The exposure of aluminum and copper to humidity may result in corrosion of the metallization and may also cause short circuits within the ICs.
To overcome these issues, platinum may be used instead of aluminum or copper as the metallization layer. Not only does platinum have excellent resistance against corrosion, it also is relatively stable at high temperatures. However, known methods of patterning platinum are unreliable. One common problem with these methods is that the patterning does not produce an appropriate feature size for the desired structures. Additionally, the known methods may introduce unacceptable levels of contaminants.